Little more than a year ago, I asked the question, “Will the Mac app store change the desktop software landscape?

The answer may not yet be obvious, but one thing is for sure: Apple’s attempt to bring the app store model to the desktop isn’t a flop.

Yesterday, the company announced that less than a year after launching, the Mac App Store has already surpassed the 100m download milestone.

According to Apple, this makes its newest app store “the largest and fastest growing PC software store in the world.

Like the App Store for iOS devices, Apple’s proposition to developers is simple: we provide a huge marketplace through which you can hawk your wares to potential customers, and we take a 30% cut of your sales.

Apple doesn’t have nearly as much control on the desktop as it does on iOS devices, where developers have no choice but to sell through the App Store. This means that Apple, in theory, has to make a much stronger case to get developers to give up 30% of the action to the company.

So far Apple seems to be doing a decent job of that, at least according to the company’s press release, which features quotes from software developers like algoriddim CEO Karim Morsy.

With just a few clicks, [our software application] for Mac is available to customers in 123 countries
worldwide. We could never have that reach through traditional channels.

The 100m download mark is certainly going to be hard for other developers to ignore, and you can be sure that Microsoft is paying attention. The next version of its OS, Windows 8, will feature the Windows Store. If Microsoft executes well enough, it’s not impossible to believe that the two most prominent consumer OSes in the world – Mac OSX and Windows – will soon be home to two of the world’s most prominent app stores.

This is certainly an interesting possibility. After all, if both Apple and Microsoft can inject app stores into mature OS ecosystems, effectively intermediating them, the desktop software landscape will have changed profoundly.